Firstly I have never bought any addons for FSX, but have recently seen a Douglas F4D Skyray from AlphaSim. I'm pretty impressed with the look of it but am not familliar with AlphaSim.
What I want to know is:
Are AlphaSim reliable and do they provide quality addons?

Here is the link :http://www.alphasim3.com/store/product_info.php?cPath=23&products_id=160

Thanks

Historically they haven't been the most comprehensive addons about. However in the past few years they have established a reputation for producing some high quality add-ons, even if they don't have the all the bells and whistles of some of the more pricey developers. The only drawback is we are now affected by the exchange rate now they are based in NZ, and price in NZ$

Personally, I'd have a look at it. You may find you really like what they produce. When I was a simmer, I did, and they produce addon's that other developers wouldn't (particularly the British types).

In all honesty Alphasim products have come on in leaps and bounds over the past few years, I still have there EFA Typhoon they released a few years ago (when doing screenshots for them) and its still one that I regularly fly around in...